Hi, Sinem, Usually in conversational English we would say, "What's your concern?", or "What's worrying you?" The question in the middle isn't common. The questions are very similar in what they ask. A concern may be a worry in some cases.

I think a person would just ask "what's wrong?". Otherwise I think number 3 would be used. Number 2 is more situational. All 3 will get the meaning across